How to make an animation in sync with a song/sound effect.

[strider213]

Say I have a background song playing.......and in the middle of the song you hear thunder.

Now I want to add a lightning "flash/flickering" animation so it goes in sync with the thunder.

I already know that I can just add in the animation on a certain keyframe and a certain time when the thunder goes.

But my question is this...

It works perfectly fine on my computer.....it is perfect in sync.

But.....on other SLOWER computers........the lightning animation sometimes comes AFTER you hear the thunder sound! There is like a 3 second delay and it's not in sync. Now I know there's a way to make it ALL in sync no matter how fast/slow your computer is.

How else do people make those animations with people talking and their mouths move in sync with the words.

If ANYBODY knows what I'm talking about please help me ASAP!

Is it something to do with FPS or cpu usage?